新型单模大模场红外硫系玻璃光子晶体光纤设计研究

Design of a novel single-mode large mode area infrared chalcogenide glass photonic crystal fibers

大模场光子晶体光纤在高功率激光传输、光纤放大器、光纤激光器中的广泛应用,使其受到研究者的广泛关注.硫系玻璃在红外波段(1—20μm)具有优良透过性能,且具有折射率高(2.0—3.5)、声子能量低(小于350cm1)、组分可调等特性,成为制备红外光纤的理想材料.本文设计一种基于Ge20Sb15Se65硫系玻璃基质的新型单模传输、低损耗、超大模场面积光子晶体光纤结构,经理论验证其在λ=10.6μm处基模限制损耗远低于0.1dB/m,高阶限制模损耗大于2dB/m,模场面积约为13333μm2.

Large mode area photonic crystal fibers （PCFs） have attracted much attention, owing to their applications in such as high power delivery, high power fibre amplifiers and fiber lasers. As an ideal candidate for fabricating mid-infrared fibers, chalcogenide glass possesses some unique advantages, such as high refractive indices （2.0-3.5）, low photon energies （lower than 350 cm^-1）, tailorable compositions, and large infrared transmission window（from 1.0 to 20 μm）. In this paper, we present a novel type of effectively single- mode chalcogenide glass Ge20Sb15Se65PCF with utra-large mode area as well as small confinement loss （lower than 0.1 dB/m for the fundamental mode, high confinement loss exceeding 2 dB/m for the higher-order mode at 10.6μm）.